Heater and test cell comprising same

Abstract

The present invention relates to a heater and a test cell comprising same, and relates to a heating unit and a test cell comprising same, the heat unit being capable of applying heat to a separator exposed to the outside from a positive electrode or a negative electrode during a test for preventing heat transfer of a battery cell, so as to rapidly induce thermal runaway, and thus can prevent an exterior material from being damaged. The test cell according to the present invention comprises: an electrode assembly; a cylindrical exterior material for accommodating the electrode assembly; and a heater bent in the circumferential direction of the exterior material, and disposed on the outer circumferential surface of the exterior material so as to generate heat, wherein the heater is disposed closer to a longitudinal end of the exterior material than to the longitudinal center of the exterior material.

Description

Heater and test cell containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0141389 filed on October 16, 2024, and all contents disclosed in the document of said Korean Patent Application are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present invention relates to a heater and a test cell including the same, and more specifically, to a heater and a test cell including the same that can prevent damage to the outer casing by rapidly inducing a thermal runaway phenomenon by applying heat to a separator exposed to the outside from the positive or negative electrode during a test to prevent heat transfer of a battery cell.

[0005]

[0006] Recently, with rising energy prices due to the depletion of fossil fuels and growing concern over environmental pollution, the demand for eco-friendly alternative energy sources has become an indispensable factor for future life. Accordingly, research on various power generation technologies, such as solar, wind, and tidal power, is ongoing, and there is also significant interest in power storage devices, such as batteries, to utilize this generated electrical energy more efficiently.

[0007] Furthermore, as technological development and demand for battery-powered electronic mobile devices and electric vehicles increase, the demand for batteries as an energy source is rapidly rising, and accordingly, much research is being conducted on batteries capable of meeting various requirements.

[0008] Batteries that store electrical energy can generally be classified into primary and secondary batteries. Primary batteries are disposable, consumable batteries, whereas secondary batteries are rechargeable batteries manufactured using materials capable of repeating oxidation and reduction processes between the electric current and the material. In other words, when a reduction reaction is performed on the material by the electric current, the power is charged, and when an oxidation reaction is performed, the power is discharged; electricity is generated as this charging and discharging cycle is repeatedly performed.

[0009] Meanwhile, as the need for large-capacity structures has recently increased, including their use as energy storage sources, the demand for battery packs that assemble multiple secondary batteries or battery modules is rising, and consequently, the demand for battery modules is also increasing.

[0010] However, as the battery module is used, heat is generated within the internal battery cells, which can sometimes spread into flames. Conventional battery modules suffer from the problem that the connectors of the battery module are destroyed by the flames generated in these cells, and thermal propagation is accelerated to adjacent battery modules through the space created by the loss of the connectors.

[0011] Therefore, in order to solve this problem, tests are being conducted to artificially apply heat to battery cells using a heater, measure the temperature of the battery cells through a thermocouple, and collect relevant data such as the temperature of the heating unit and battery cells when heat transfer occurs.

[0012] At this time, when performing the above test, as the battery cell was exposed to high temperatures for a longer period, the strength of the outer casing housing the electrode assembly of the battery cell decreased significantly, and as a result, there was a problem in which the outer casing was damaged in the form of tearing.

[0013]

[0014] The present invention has been devised to solve the above-mentioned problems, and the objective of the present invention is to provide a heater and a test cell including the same that can prevent damage to the outer casing by rapidly inducing a thermal runaway phenomenon by applying heat to a separator exposed to the outside from the positive or negative electrode during a test to prevent heat transfer of a battery cell.

[0015]

[0016] A test cell according to the present invention comprises an electrode assembly, a cylindrical outer casing that accommodates the electrode assembly, and a heater formed to be bent along the circumferential direction of the outer casing and disposed on the outer surface of the outer casing to generate heat, wherein the heater is disposed closer to the longitudinal end of the outer casing than to the longitudinal center of the outer casing.

[0017] The heater comprises a plurality of straight sections extending along the longitudinal direction of the exterior material and a connecting section connecting each of the adjacent straight sections, and the connecting section can be elastically deformed along the radius of curvature of the outer surface of the exterior material.

[0018] The thickness of the above heater may be 0.5 mm or less.

[0019] The above heater may be formed including Inconel material.

[0020] The electrode assembly is a jelly-roll type electrode assembly in which an anode, a separator, and a cathode are wound, and the heater may be disposed on the outer surface of the outer casing covering the end of the separator exposed to the outside from the anode or the cathode.

[0021] The heater may be located within one-third of the length of the exterior material from the longitudinal end of the exterior material.

[0022] The heater may be located within 20 mm from the longitudinal end of the exterior material.

[0023] The heater according to the present invention is a heater disposed in a cylindrical outer material, formed to be bent along the circumferential direction of the outer material, disposed on the outer surface of the outer material to generate heat, and disposed closer to the longitudinal end of the outer material than to the longitudinal center of the outer material.

[0024] The heater includes a straight section extending along the longitudinal direction of the exterior material and a connecting section connecting adjacent straight sections so that the straight section extends in a zigzag pattern, and the connecting section can be elastically deformed along the radius of curvature of the outer surface of the exterior material.

[0025] The heater may have a thickness of 0.5 mm or less.

[0026] The heater can be formed including Inconel material.

[0027] The above-mentioned outer material accommodates a jelly-roll type electrode assembly in which an anode, a separator, and a cathode are wound, and the heater may be disposed on the outer surface of the outer material covering the end of the separator exposed to the outside from the anode or the cathode.

[0028]

[0029] The heater according to the present invention and the test cell including the same have the effect of preventing damage to the outer casing by rapidly inducing a thermal runaway phenomenon by applying heat to the separator exposed to the outside from the positive or negative electrode during a test to prevent heat transfer of a battery cell.

[0030]

[0031] FIG. 1 is a perspective view of a test cell according to the present invention.

[0032] FIG. 2 is a front view showing the detailed configuration of a heater according to the present invention.

[0033] FIG. 3 is a cross-sectional view illustrating the internal configuration of a test cell according to the present invention.

[0034] Figure 4 is a magnified view of area A of Figure 3.

[0035]

[0036] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0037] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0038] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0039]

[0040] test cell

[0041] FIG. 1 is a perspective view of a test cell according to the present invention, FIG. 2 is a front view showing the detailed configuration of a heater according to the present invention, FIG. 3 is a cross-sectional view showing the internal configuration of a test cell according to the present invention, and FIG. 4 is a partial enlarged view of area A of FIG. 3.

[0042] Referring to FIGS. 1 to 4, the test cell (1) according to the present invention may include an electrode assembly (100), an outer material (200), and a heater (300).

[0043] As the temperature of a battery cell including an electrode assembly (100) and an outer material (200) rises, thermal propagation may occur. The test cell (1) according to the present invention can monitor and collect temperature data necessary to prevent thermal propagation by applying heat of various temperatures to the outer material (200) and measuring the temperature of the outer material (200) and the temperature of the heat applied to the outer material (200) to cause the thermal propagation.

[0044] The electrode assembly (100) may be a jelly roll type electrode assembly wound with a separator (130) interposed between a long sheet-type positive electrode (110) and a negative electrode (120) coated with an active material. Here, the positive electrode (110) is provided with a positive electrode tab (not shown) that is coupled to an outer casing (200), and the negative electrode (120) is provided with a negative electrode tab (not shown) that is coupled to an outer casing (200). At this time, the jelly roll type electrode assembly has the advantage of being easy to manufacture in a cylindrical shape and having a high energy density per unit weight.

[0045] The outer material (200) can accommodate the electrode assembly (100) and the electrolyte.

[0046] In the drawings below, the circumferential direction of the exterior material (200) is indicated as the "X direction," and the length direction of the exterior material (200) is indicated as the "Y direction."

[0047] The outer material (200) can be configured to include a metal layer, such as an aluminum thin film, to protect internal components such as the electrode assembly (100) and the electrolyte, and to improve electrochemical properties and heat dissipation properties of the electrode assembly (100) and the electrolyte.

[0048] The outer material (200) can be classified according to its shape into a can-type secondary battery in which the electrode assembly (100) is embedded in a metal can and a pouch-type secondary battery in which the electrode assembly is embedded in a pouch of an aluminum laminate sheet.

[0049] Meanwhile, the shape of the exterior material (200) according to the present invention is not limited, but it is preferable to form it in a cylindrical shape as shown in FIG. 1.

[0050] The heating unit of the test cell (1) according to the present invention is configured to test heat transfer, and the heating unit may include a heater (300) and a thermocouple (not shown).

[0051] A heater (300) can be placed on the outer surface of the exterior material (200) and can generate heat to heat the exterior material (200) and the electrode assembly (100).

[0052] In order to attach the heater (300) to the outer surface of the cylindrical outer surface (200), the heater (300) may be formed to be bent along the circumferential direction of the outer surface (200). Therefore, since the heater (300) needs to be easily bent along the radius of curvature of the outer surface of the outer surface (200), it is desirable for the thickness of the heater (300) to be formed as thin as possible. As a specific example, the thickness of the heater (300) may be 0.5 mm or less.

[0053] In addition, to prevent ignition and corrosion of the heater (300), the heater (300) may be formed by including an Inconel material that has excellent heat resistance and corrosion resistance. The Inconel material has the advantages of good heat resistance, high rigidity, and excellent oxidation resistance even at high temperatures of 900 degrees or higher.

[0054] As a specific example, the above Inconel material may be Inconel 600. Inconel 600 is an alloy comprising 15.5 weight% chromium (Cr), 6 to 7 weight% iron (Fe), and the remainder being nickel, which has good heat resistance, excellent mechanical properties, and resistance to corrosion.

[0055] The heater (300) according to the present invention is positioned on the outer surface of the exterior material (200), and may be positioned closer to the longitudinal end of the exterior material (200) than to the longitudinal center (500) of the exterior material (200). For example, the heater (300) may be positioned closer to the uppermost end (200a) of the exterior material (200) than to the longitudinal center (500) of the exterior material (200). For another example, the heater (300) may be positioned closer to the lowermost end (200b) of the exterior material (200) than to the longitudinal center (500) of the exterior material (200).

[0056] Meanwhile, if the positive electrode (110) and the negative electrode (120) come into direct contact, a short circuit may occur, which may result in a thermal runaway. To prevent this, the separator (130) can block physical contact between the positive electrode (110) and the negative electrode (120).

[0057] Here, when the temperature inside the outer material (200) rises due to heat generated from the heater (300), the separator (130) contracts, and since the end of the separator (130) is exposed from the anode (110) or cathode (120), the contraction speed may be faster than that of the center.

[0058] In the test cell (1) according to the present invention, since the heater (300) is positioned closer to the longitudinal end of the outer material (200) than to the longitudinal center (500) of the outer material (200), the shrinkage of the separator (130) proceeds more quickly, and accordingly, the short circuit phenomenon caused by contact between the anode (110) and the cathode (120) is accelerated, so thermal runaway may occur more quickly.

[0059] At this time, during the heat transfer test, if the thermal runaway phenomenon is delayed, the time the exterior material (200) is exposed to high temperature increases, so the exterior material (200) may tear.

[0060] Considering that the heat transfer test according to the test cell (1) is intended to obtain temperature information necessary for the occurrence of heat transfer, the test cell (1) according to the present invention has the effect of preventing damage to the exterior material (200) that may occur during the heat transfer test by causing the heat runaway phenomenon as quickly as possible.

[0061] The heater (300) of the test cell (1) according to the present invention may be placed at the end of the outer surface of the exterior material (200).

[0062] For example, the heater (300) may be placed in an outer covering (200) that covers the top of the separator (130) exposed to the outside from the anode (110) or cathode (120). For another example, the heater (300) may be placed in an outer covering (200) that covers the bottom of the separator (130) exposed to the outside from the cathode (120) or anode (110).

[0063] The heater (300) may be located within one-third of the length of the exterior material (200) from the longitudinal end of the exterior material (200). Preferably, the heater (300) may be located within 20 mm from the longitudinal end of the exterior material (200).

[0064] Specifically, when the outer surface of the exterior material (200) is divided equally into three parts along the length direction (Y direction), the outer surface of the exterior material (200) can be divided into an upper region (S1), a middle region (S2), and a lower region (S3).

[0065] At this time, the heater (300) can be placed in the upper area (S1) or the lower area (S3).

[0066] For example, the heater (300) may be positioned in the upper area (S1) but within a range that does not extend beyond the upper area (S1). That is, the lowest part of the heater (300) may be positioned at the same level as or higher than the lowest part of the upper area (S1).

[0067] As another example, the heater (300) may be positioned in the lower area (S3) but within a range that does not extend beyond the lower area (S3). That is, the uppermost part of the heater (300) may be positioned at the same level as or lower than the uppermost part of the lower area (S3).

[0068] When the heater (300) is placed in the upper region (S1) or lower region (S2) of the outer surface of the exterior material (200), the position where the separator (130) is exposed from the positive electrode (110) or negative electrode (120) and the position of the heater (300) become as close as possible. Accordingly, the heat generated from the heater (300) is transferred to the end of the separator (130) with minimal loss, thereby increasing the shrinkage speed of the separator (130) and causing thermal runaway to occur quickly, which can prevent damage to the exterior material (200).

[0069] The heater (300) according to the present invention may be an electric heater including an electric resistor and may be connected to an external wire (400).

[0070] The thermocouple of the heating unit according to the present invention can measure the temperature of at least one of the outer material (200) and the heater (300). The thermocouple may be a temperature sensor in the form of a wire, and information sensed through the thermocouple is transmitted to a sensing unit (not shown) via a wire, and the sensing unit can obtain temperature information of a battery cell including an electrode assembly (100) and an outer material (200). At this time, the heater (300) can generate heat up to a maximum temperature at which no heat transfer occurs, and the thermocouple can measure the maximum temperature to obtain information about the minimum temperature at which heat transfer occurs.

[0071] The heater (300) may consist of a straight section (310) and a connecting section (320).

[0072] The straight section (310) may be composed of multiple straight sections, and each straight section (310) may be extended along the length direction (Y direction) of the exterior material (200). At this time, the length (L) of the straight section (310) may be 40 mm or less. Additionally, an external wire (400) may be connected to the end of the straight section (310) positioned at the outermost edge.

[0073] The connecting part (320) can connect each adjacent straight part (310).

[0074] The heater (300) according to the present invention may have a sum of widths (W) of the connecting portions (320) formed to be relatively longer than that of a heater used in a conventional battery cell. As a specific example, the sum of the widths (W) of the connecting portions (320) may be 16.5 mm or more.

[0075] The heater (300) according to the present invention may have a ratio of the sum of the widths (W) of the connecting portion (320) to the length (L) of the straight portion (310) of 0.4 or more.

[0076] When the heater (300) is attached to the outer surface of the exterior material (200), the connecting part (320) is bent along the width direction, so the connecting part (320), which is relatively wider than the existing one, can be easily bent along the circumferential direction of the exterior material (200).

[0077] Additionally, when the heater (300) is attached to the outer surface of the exterior material (200), the connecting part (320) is bent along the circumferential direction (X direction) of the exterior material (200), so the connecting part (320) can be deformed elastically along the radius of curvature of the outer surface of the exterior material (200).

[0078] Since the outer material (200) housing the jelly roll-type electrode assembly (100) is cylindrical, the outer surface of the outer material (200) has a curvature, making it difficult to easily attach the heater (300). However, the test cell (1) according to the present invention has the effect of being easily attached to the cylindrical outer material (200) because the connecting part (320) can be easily bent along the circumferential direction of the outer surface of the outer material (200).

[0079]

[0080] Heating unit

[0081] Referring again to FIG. 2, the heating unit according to the present invention may include a heater (300) and a thermocouple (not shown).

[0082] The heater (300) can be placed on a cylindrical exterior material, formed to be bent along the circumferential direction of the exterior material (200), placed on the outer surface of the exterior material (200) to generate heat, and can be placed closer to the longitudinal ends (200a, 200b) of the exterior material (200) than to the longitudinal center (500) of the exterior material (200).

[0083] At this time, the above components mentioned in the heating unit may be based on the description of each component of the test cell (1) according to the present invention described above.

[0084] According to this heating unit, the position where the separator (130) is exposed from the anode (110) or cathode (120) and the position of the heater (300) are brought as close as possible. Therefore, the heat generated from the heater (300) is transferred to the end of the separator (130) with minimal loss, thereby increasing the shrinkage speed of the separator (130) and causing thermal runaway to occur quickly, which can prevent damage to the outer material (200).

[0085] Considering that the heat transfer test according to the test cell (1) is intended to obtain temperature information necessary for heat transfer, the heating unit has the effect of preventing damage to the exterior material (200) that may occur during the heat transfer test by causing heat runaway as quickly as possible.

[0086]

[0087] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0088]

[0089] [Explanation of the symbol]

[0090] 100: Electrode assembly

[0091] 110: Anode

[0092] 120: Cathode

[0093] 130: Separator

[0094] 200: Exterior materials

[0095] 300: Heater

[0096] 310: Straight section

[0097] 320: Connection

Claims

1. Electrode assembly; A cylindrical outer casing for housing the electrode assembly; and A heater formed to be bent along the circumferential direction of the exterior material and disposed on the outer surface of the exterior material to generate heat; comprising The above heater is, A test cell disposed on the outer surface of the exterior material, which is positioned closer to the longitudinal end of the exterior material than to the longitudinal center of the exterior material, and covers the end of the separator exposed to the outside from the anode or cathode of the electrode assembly.

2. In Paragraph 1, The above heater is, A plurality of straight sections extending along the longitudinal direction of the above exterior material; and Includes a connecting part connecting each of the adjacent straight sections; The above connecting part is, A test cell that deforms elastically along the radius of curvature of the outer surface of the above exterior material.

3. In Paragraph 1, A test cell in which the thickness of the heater above is 0.5 mm or less.

4. In Paragraph 1, The above heater is, A test cell formed including Inconel material.

5. In Paragraph 1, The above electrode assembly is, A test cell characterized by the anode, the separator, and the cathode being a wound jelly-roll type electrode assembly.

6. In Paragraph 1, The above heater is, A test cell located within one-third of the length of the exterior material from the longitudinal end of the exterior material.

7. In Paragraph 1, The above heater is, A test cell located within 20mm from the longitudinal end of the above exterior material.

8. A heater placed in a cylindrical exterior material, A heater disposed on the outer surface of the exterior material, formed to be bent along the circumferential direction of the exterior material, and disposed to generate heat, positioned closer to the longitudinal end of the exterior material than to the longitudinal center of the exterior material, and covering the end of the separator exposed to the outside from the positive or negative electrode of the electrode assembly housed in the exterior material.

9. In Paragraph 8, A straight section extending along the longitudinal direction of the above exterior material; and A connecting part connecting adjacent straight sections so that the straight section extends in a zigzag pattern; The above connecting part is, A heater that deforms elastically along the radius of curvature of the outer surface of the above exterior material.

10. In Paragraph 8, A heater with a thickness of 0.5 mm or less.

11. In Paragraph 8, A heater formed including Inconel material.

12. In Paragraph 8, The above electrode assembly is, A heater characterized by the anode, the separator, and the cathode being a jelly-roll type electrode assembly in a wound form.

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